In an indoor radio frequency (RF) communication channel, small scale fading can vary the local average power of the received signal, between points as close as a fraction of a wavelength apart. At the same time, the presence of obstacles and motion of scatterers around low-level portable antennas, give rise to rapid and sharp changes in the mean signal level. Hence, large scale shadowing in indoor wireless environment, has a correlation distance of around 1 - 2 m. In such a scenario, large scale shadowing can vary the local mean of the received signal envelope, between points separated by...